A study of the effects of storage methods on the quality of maize and household food security in Rungwe District, Tanzania.

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A STUDY OF THE EFFECTS OF STORAGE METHODS ON THE QUALITY OF MAIZE AND HOUSEHOLD FOOD SECURITY IN RUNGWE DISTRICT, TANZANIA

By Rose Mboya

THESIS SUBMITTED IN FULL FULFILMENT OF THE REQUIREMENT FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN FOOD SECURITY

SCHOOL OF AGRICULTURAL SCIENCES AND AGRIBUSINESS, UNIVERSITY OF KWAZULU-NATAL

October 2011

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Declaration

I, Rose Mboya, declare that:

(i) The research reported in this thesis, except where otherwise indicated, is my original research.

(ii) This thesis has not been submitted for any degree or examination at any other university.

This thesis does not contain other person’s data, pictures, graphs or other information, unless specifically acknowledged as being sourced from those persons.

(iii) This thesis does not contain other authors’ writing, unless specifically acknowledged as being sourced from other authors. Where other sources have been quoted, then:

a) their words have been re-written but the general information attributed to them has been referenced;

b) where their exact words have been used, their writing has been placed inside quotation marks, and referenced.

(v) This thesis does not contain text, graphics of tables copied and pasted from the internet, unless specifically acknowledged, and the source being detailed in the thesis and in the references sections.

Signed………Date………..

Rose Mboya (student)

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Signed………Date………

Prof. Pangirayi Tongoona (Supervisor)

Prof. John Derera (Co-supervisor)

Dr. Maxwell Mudhara (Co-supervisor)

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Abstract

A sample of 260 farm households that were randomly selected in Katumba ward, Rungwe district, Tanzania were studied for the effects of storage methods on the quality of maize grain and household food security using qualitative and quantitative methods. Maize storage problems, amounts of maize that farm households harvested and amounts of maize that farm households lost to pests per year, food security status and farm households’ perceptions concerning their food security status were investigated using face - to - face semi - structured and structured interviews.

Common storage methods that farm households used to store maize and the dietary importance of maize were investigated through interviews, seasonal calendars and the matrix for scoring and ranking. The quality of maize was investigated through conducting mycological analysis and through investigating levels of insect infestation using the incubation method on maize samples collected from a sub-sample of 130 farm households at harvest and after five months of storage period.

It was found that farm households in Katumba ward preferred maize meal rather than other types of food that provide bulk such as rice and green bananas/plantains. Maize contributed 66.8 % - 69.5 % of the total energy and 83 - 90 % of the total protein required per day, and farm households stored maize using roof and sack storage methods. It was also found that 34.5 % of 2323 tonnes of maize that were harvested per annum in Katumba ward were lost to pests during storage. Fusarium, Diplodia, Aspergillus and Penicilliums species were identified as the main fungal pathogens that attacked stored maize. Sitophilus zeamais, Sitotroga cerealella and rodents were also identified as the main maize storage pests. About 25 % of the maize samples that were collected at harvest and 93 % of the maize samples that were collected from the same farm households after five months of storage were infested by either Sitophilus zeamais or Sitotroga cerealella or both. Maize samples from the two storage systems had an average number of 80 insect pests per 120 maize kernels (or 51 g of maize), amounting to 1569 insects per kg. The high levels of insect infestation reduced the amount of maize that could have been available to the farm households and subjected stored maize to fungal infections and subsequent contaminations, thus, rendering the farm households vulnerable to food insecurity. Furthermore, it was also found that most of the infestation of maize by insect pests and moulds in Katumba ward occurred during storage, and that farm households were not well informed concerning maize storage and

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the negative effects that fungal activities in maize can have on the health of the consumers. An average of 87717 µg/kg fumonisins, 596 µg/kg aflatoxins, 745 µg/kg ochratoxins and 1803 µg/kg T-2 toxins were detected in the maize samples. Currently, there are no set standards for T-2 toxins, whereas the internationally accepted standards for aflatoxins, fumonisins and ochratoxins in cereals are 20 µg/kg, 4 mg/kg and 50 µg/kg, respectively. It was concluded that the levels of mycotoxins detected in maize from Katumba ward were far above the internationally accepted standards and that the farm households were at risk of ill health through consuming maize meals made from contaminated maize grain. The presence of high concentrations of mycotoxins, together with the high levels of insect infestation in the maize led to the conclusion that reduction of the nutrient content of the maize grain in Katumba ward was inevitable. Thus, the pests that infested maize stored using the roof and sack storage methods in this ward compromised not only the availability of food, but also the utilization of the nutrients in the maize and its safety, leading to the farm households’ food insecurity.

It was further concluded that the quality of maize stored using roof and sack storage methods in Katumba ward was low and that the roof and sack storage methods were inadequate for protecting stored maize from pests. It was recommended that an efficient method for rapid drying of maize prior to storage be found, that the roof and sack storage methods be improved so that they can effectively protect stored maize from moisture content problems. It was also recommended that the farm households’ awareness concerning maize storage and food security be raised, and that the extension staff in Katumba ward should urge the Tanzanian government to implement an agricultural policy which promotes efficient maize storage and maize quality in order to improve the current status quo. Above all, since maize is the predominant staple, it was recommended that the maize breeding program in Tanzania should emphasize development of maize varieties that are resistant to ear rots, storage insects and to contamination by mycotoxins as part of a larger program to improve food security in this part of the country. Breeding programs that aim at enhancing the nutritional value of maize were also recommended.

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Dedication

To my family

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Acknowledgements

Field and laboratory work for this study was funded by the International Development and Research Centre (IDRC), Canada.

I am sincerely grateful to my supervisory team, Professor, P. Tongoona, Dr. John Derera, Dr.

Maxwell Mudhara and Dr. Augustine Langyintuo for their tireless guidance and support.

I am also grateful for Dr. Sackey Yobo’s guidance throughout all of the laboratory work. I would also like to thank the Discipline of Plant Pathology, University of KwaZulu-Natal, for making it possible for me to use the laboratory facilities and the Electronic microscopy team for tirelessly helping with taking necessary pictures.

Furthermore, I am thankful to Dr. Muthulisi Siwela for supervision during the initial stages of this study, and Marylyn Christian, for her support during the initial stage of the laboratory work.

My gratitude also goes to Jacques Ibaba, Benice Sivparsad, Lucy Chibambo, Prof. Isabel Phiri, Dr Maxwell Phiri, Dr. Julia Sibiya, the Electronic Microscopy team, UKZN and Prof. Theresa Coetzer.

I also thank my brothers, Ikundwila and Benard Mwalwisi for tirelessly supporting me throughout data collection. I am sincerely grateful to my children, Michael, David and Faraja, and my mother, Tamali Sakuna, for their incredible understanding and support. Lastly, but not least, I would like to thank Mike Mboya, and all of those whose names have not been included on this list, who assisted in one way or another.

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maize...194 6.9 Concentration of fumonisins in the maize sample extracts (mg/3 g of maize)...195 6.10 Quantities of aflatoxins in the maize samples (μg/3 g of maize)...195 6.11 Quantities of T-2 toxins in the maize samples (µg /3 g of maize) (n=38)...196 6.12 Quantities of ochratoxins in the maize samples (µg /2 g of maize)...196 6.13 The quantities of the mycotoxins (μg) that an individual in a farm household in Katumba ward

could consume per meal………...197 6.14 The estimated quantities of mycotoxins per kg of maize...198 6.15 Comparing the difference between the mean scores for the quantities of mycotoxins per kg of

maize stored using the roof and the sack storage methods...199 6.16 Comparing the mean quantities of mycotoxins in maize stored in different forms...200 7.1 Food security scale score standard values... ...220 7.2 Transport facilities that the farm households were in possession of (n=260)………..223 7.3 Communication facilities that the farm households owned (n=260)...223 7.4 Quantities of cows, goats and pigs that farm households owned (n=260)...225 7.5 Means that farm households used for transporting maize from the fields (n=260)...225 7.6 Persons in the farm households who own the hand hoes (n=260)...226 7.7 Persons who owned transport and transportation facilities in the farm households (n=260)..……....226 7.8 Persons who owned communication facilities in the farm households (n=260)... ...227 7.9 Persons in the households who owned livestock (n=260... ...228 7.11 Farm households' estimated yearly income {(TS), (n=260)}... ...229 7.12 Legume crops that farm households grew (n=260)... ...231 7.13 Types of vegetables grown by the farm households grew (n=260)... ...231 7.14 Types of food that farm households often ate together with maize meals (n=260)...232 7.15 Types of food that the farm households utilized in times of maize scarcity (n=260)...232 7.16 Sources of the other types of food that farm households utilized when maize was scarce

(n=260)...233

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7.17 Strategies used by the farm households when maize was scarce (n=260)...233 7.18 Time in a year when farm households started using other types of food in order to cope with

maize shortages (n=260)... ...235 7.19 Reasons that the farm households provided for perceiving themselves food secure

(n=260)... ...235 7.20 Reasons that the farm households provided for perceiving themselves food insecure (n=260)...236

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List of Figures

Figure Page

2.1 Sack storage...…...35 2.2 Storage cribs………...37 2.3 A storage basket………..……...38 2.4 Concrete silo………...39

2.5 a Brick silo..………..………...40

2.5 b A cross-section through a mud brick silo...………...40 2.6 Metal silo……….41 2.7 Roof storage………...42 2.8 Location of Katumba ward in Rungwe district, Mbeya region, Tanzania………...46 3.1 Number of maize meals that the farm households consumed daily……….69 3.2 Number of days per week during which the farm households consumed maize meals……..70 3.3 Total number of meals that the farm households consumed per day……...70 3.4 Types of food that the farm households concurrentlyate concurrently withmaize

meals………....75 3.5 Reasons for which the farm households preferred maize meals...76 4.1 Sampling of the maize sample units………...94 4.2 Comparison of levels of insect infestation on maize samples infested prior to storage with

that of maize collected from the same farm households after five months of storage

period………..114 4.3 Household heads' years of formal education in Katumba ward………...117 4.4 Age of farm household heads in Katumba ward………...117 6.1 Types of pathogenic fungi identified in the maize samples...……….………...185 6.2 Fungi colonies observed in the maize samples …….………...186 6.3 Fusarium conidia viewed under the light microscope……….………...186 6.4 Penicillium spores viewed under the light microscope……….187 6.5 Penicillium species viewed under the electronic microscope………...187 6.6 Aspergillus species viewed under the light microscope (left) and the

Zeis LSM 710 (Confocal) DIC imager……….………187

6.7 Types of mycotoxins in the maize samples………...191

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7.1 Number of chickens per household …………...……….………..224 7.2 Time in a year during which farm households changed the number of meals that they

take perday...230 7.3 Month in a year when farm households applied strategies to cope with maize scarcity...234

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CHAPTER ONE INTRODUCTION

1.1 The importance of maize in sub-Saharan Africa

Maize (Zea mays L) is the third most important food crop in the world (Escobedo, 2010;

Organization for Economic Co-operation and Development (OECD) and the Food and Agriculture Organization of the United Nations (FAO), 2010) and it is a staple food crop in Africa (Bryceson, 2009; M’mboyi et al., 2010). It is estimated that at least 40 million tonnes of maize are produced in sub-Saharan Africa annually {FAO Statistics (FAOSTAT), 2010 a}, which accounts for 35 % of the total amount of maize produced in the world (Mukanga, 2009). Table 1.1 shows estimated amounts of maize that were produced in 1998 - 2007 in sub-Saharan Africa.

Table 1.1: The estimated amounts of maize produced in Africa in 1998-2007 (Tonnes)

Year Amount of Maize

Produced (1000 tonnes)

1998 40,113

1999 42,398

2000 44,284

2001 41,384

2002 44,786

2003 45,586

2004 47,562

2005 49,864

2006 49,617

2007 47,737

Source: FAOSTAT (2010 a)

Statistics from 12 selected countries in sub-Saharan Africa (Table 1.2) confirm the claim that maize is not only produced but also consumed widely in this region, which further sheds light on the extent to which maize is an important food crop in this continent. It is estimated that maize accounts for 40 % of the total dietary intake of consumers in southern and eastern Africa (Mugo et al., 2002). It is a good source of carbohydrates, it consists of protein and small quantities of fat, vitamins, dietary fibres and minerals such as iron and phosphorus (Klopfenstein, 2000; Iken et

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al., 2002), and it can be stored for extended periods. Thus, maize is a key crop in ensuring availability of food and ensuring food security among the poor communities in sub-Saharan Africa.

Table 1.2: Estimated average maize production and consumption in 12 selected countries in sub- Saharan Africa (1998 - 2007)

Country Maize production per annum (1000 tonnes)

Per capita consumption (kg per annum)

Total consumption per annum (1000 tonnes)

Angola 535 37.40 578.90

Cameroon 929 39.20 659.30

Ghana 1,142 40.70 842.70

Kenya 2,654 83.80 2810.2

Malawi 1,832 128.90 1506.3

Mozambique 1,164 57.30 1114.70

Nigeria 5,474 21.40 2924.80

South Africa 9,010 108.70 5056.00

Tanzania 3,161 112.50 2385.60

Uganda 1,153 27.50 726.30

Zambia 993 119.80 1326.90

Zimbabwe 1,321 114.50 1425.30

Source: FAOSTAT (2010 a, b; Katinila et al, 1998)

The wide variation in the per capital consumption of maize in Table 2 shows that the extent of the importance of maize as a source of food differs from country to country in sub-Saharan Africa.

1.2 The importance of maize in Tanzania

In Tanzania maize is the dominant staple food crop (Government of the United Republic of Tanzania, 2000; Amani, 2004). It is estimated that over 80 % of the population of Tanzania depends on maize for food (Bisanda and Mwangi, 1996). Although FAOSTAT’s (2010 a) report indicates a lower figure for the annual per capita consumption of maize in Tanzania, Katinila et al. (1998) estimated that maize contributes up to 60 % of the total energy in the diets of the consumers in Tanzania, and that the annual per capita consumption of maize in Tanzania is 112.5 kilograms and that this amounts to three million tonnes of maize consumed annually.

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Nevertheless, the maize potential in relation to ensuring availability of food in Tanzania is not being fully realized because 34 % (Kimenju and De Groote, 2010) of the maize produced is lost due to inadequate post-harvest management (Government of the United Republic of Tanzania- Ministry of Agriculture, 2006; Makundi et al., 2006), of which poor storage methods and maize seeds susceptibility to storage pests attack play major roles. Inadequate storage technologies jeopardize not only the amount of maize that the consumers can access, but also the quality of stored maize. High quality maize is that which is rich in nutrients and free from pathogens and physical and chemical contaminants (Weinberg et al, 2008, Golob, 2004).

1.3 Maize storage problems and maize quality

The greatest setback during maize storage is that it is susceptible to attack by pests, of which insect pests (Makate, 2010), moulds (Weinberg et al., 2008) and rodents {International Research Institute (IRRI) and International Maize and Wheat Improvement Centre (CIMMYT), 2009} top the list. The attack of stored maize by storage pests is associated with loss of millions of tonnes of stored maize through insects infestations (Dhliwayo and Pixley, 2003) and through attack by rodents and moulds (Compton and Sherington, 1999). It is estimated that 30 - 40 % of cereal grains, 45 % of roots and tubers and 40 - 80 % of vegetables and legumes produced in Tanzania are lost to pests and diseases (Government of the United Republic of Tanzania-Ministry of Agriculture, 2006). As a result of the crop losses, consumers access inadequate amounts of food, which in turn has led to malnutrition, anaemia, energy and vitamin deficiencies being common in Tanzania (Government of the United Republic of Tanzania-Ministry of Agriculture, 2006).

However, whether the figures indicated by the Government of the United Republic of Tanzania (2006) concerning the amounts of food crops lost to pests are based on scientific estimations is not known.

The outcomes of the attack also include loss of maize quality (IRRI and CIMMYT, 2009), which includes reduction in the nutrient content of the maize (Jood et al., 1992). Stored maize can also become unsafe for consumption as a result of contamination by waste products and mycotoxins where moulds are concerned {Sallam, 1999; Weinberg et al., 2008; Somali Agriculture Technical Group (SATG), 2009}. On-farm storage technologies play a major role in determining the quality of stored maize and determine quantities of maize that can be available to the consumers

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(Thamaga, 2001; Thamaga-Chitja et al., 2004; Golob, 2004). In turn this improves not only the purchasing power of the farm households by making it possible for them to market the maize and raise income for purchasing non-farm products and food commodities that they do not produce, but it also contributes to poverty alleviation and food security of the consumers.

Moisture content of the grains, humidity, temperature, foreign materials in maize and poor handling of the maize prior to storage are factors that influence the development of micro- organisims in stored maize, which eventually cause maize losses and contaminations (Weinberget al., 2008; Murdolelono and Hosang, 2009). Contamination of food products by mycotoxins have been reported worldwide (Wild and Gong, 2010), and over 300 types of mycotoxins have been identified, out of which 20 types have been found to occur naturally in foods and feeds {Institute of Food Science and Technology (IFST), 2009}. Fusarium,Aspergillus and Penicillium species have been identified as the most important types of fungi that infest stored maize and produce mycotoxins which are harmful to both human beings and animals (Sweeney et al., 2000; Bennet and Klich, 2003; Ngoko et al., 2008; Wild and Gong 2010). Mycotoxins that are produced by the indicated fungal species include fumonisins and T-2 toxins which are mainly produced by Fusarium species (Atkins and Norman, 1998, Akande et al., 2006), aflatoxins which are produced by Aspergillus species (D’Mello and Macdonald, 1997; Cousin et al., 2005; Perduri and Gobba, 2009) and ochratoxins which are mainly produced by Penicillium and some Aspergillus species such as Aspergillus niger (Cousin et al., 2005, Magalhãesa and Bernado, 2010).

While contaminations of cereal products have been reported in several countries in the world (Wild and Gong, 2010), alarming concentrations of mycotoxins in maize have been reported in developingcountries (IFST, 2009). In Africa, outbreaks of diseases and deaths associated with the ingestion of foods and feeds that are made from maize that is contaminated with mycotoxins have been reported (Wild and Gong, 2010). Consumption of maize which is contaminated by the mycotoxins may lead to diseases such as cancer and kidney problems (Hayes, 2000; Munkvold et al., 2009). Other diseases that mycotoxins cause include suppression of the immune system, interference with neurone function and protein synthesis, and retarded growth (Hayes, 2000;

Munkvold et al., 2009). Death may also occur as a result of chronic exposure to high levels of mycotoxins (Hayes, 2000; Munkvold et al.,2009). In 2004 death of more than 100 people in

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Eastern Kenya was associated with consumption of maize meals that had high levels of aflatoxins. Outbreaks of illnesses coused by consumptions of high levels of mycotoxins were also reported in 2005 and 2006 in Kenya (Muthoni et al., 2009). Much of the contamination of commodities by mycotoxins has been associated with inadequate storage technologies and climatic conditions such as high humidity, dampness and temperatures {World Health Organization (WHO), 2006; Williams, 2004; Gourama and Bullerman, 1995; Tachin, 2008}.

This shows that storage technologies play a major role in determining the quality of maize. Thus, ensuring maximum efficiency of the storage technologies is crucial to the safety of stored maize and health of the consumers.

1.4 The Nutrient deficiency of maize

Maize is deficient in the essential amino acids lysine and tryptophan, thus, the protein which is found in maize is of low quality (Friedman, 1996; Escobedo, 2010). This, together with its deficiency in minerals and vitamins, means that maize may subject the consumers to poor nutrition especially in places where it is the staple food crop. This robs the consumers of nutrition security and subjects them to food insecurity. The nutrient deficiency of maize is being addressed through breeding and molecular technologies that aim at not only improving maize yield, but also improving and enhancing its nutrient content (Ortiz-Monasterio et al., 2007). However, in Tanzania breeding technologies are focused on improving maize seeds for high yield. The susceptibility of maize seed to attack by pests, together with the use of inefficient storage technologies especially among small scale farmers in Africa are still hindering achievent and maintainance ofthe highest quality of maize (Adda et al.,2002).

1.5 Food security in Sub Saharan Africa 1.5.1 Food security defined

The definition of food security has been evolving over time (Maxwell, 2001; Babu and Sanyal 2009) due to the progressive shifts in the concern regarding issues that are central to food security. While initially food security was concerned with issues of global and national food supply, with time, issues of household and individual access to food and consumption, nutrition and health have become important components (Maxwell, 2001). In the current study, FAO’s (2010) recent and a more inclusive definition of food security applies. It states that “Food

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security exists when all people, at all times, have physical, social, and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life”. Household food security is the application of this concept to the family level, with individuals within households as the focus of the concern.

In view of the FAO’s (2010) definition, unlimited availability of nutritious preferred food, access to the food and the degree to which the food is safe for consumption are components of food security. There are four main factors that determine food security, namely: food availability, food access, food utilization (Babu and Sanyal, 2009) and stability {World Food Programme (WFP), 2009}. While ‘availability’ is concerned with food supply, ‘access’ is the ability of an individual or household to get food, ‘utilization’ is the capacity that an individual has regarding selecting, and taking in the nutrients in food and ‘stability’ has to deal with unlimited availability and access to food, and unlimited utilization of the food (WFP, 2009). Several factors are used as indicators of food security, namely: the amount of food that people consume, the quality of the food in terms of its nutrient content, food diversification (Smith et al., 2006) and wealth in terms of the amount of income levels. The quantity of assets that people own is also an indicator of food security (Maxwell and Smith, 1992). Through these food security indicators, it is possible to estimate the degree to which people have access to food and to predict whether people are able to purchase food when their food supplies run out.

1.5.2 The state of food insecurity in sub-Saharan Africa

Food insecurity is the opposite of food security, and it manifests itself through hunger or vulnerability to hunger, which WFP, 2009 defines as ‘a condition in which people lack the required nutrients, both macro (energy and protein) and micro (vitamins and minerals) for fully productive, active and healthy lives’. Hunger can be short term/acute or longer term/chronic, and has a range of mild to severe effects. It can result from insufficient nutrient intake or from people’s bodies failing to take in the required nutrients (WFP, 2009). Severe nutrient deficiencies can lead to sickness and death {Administrative Committee Coordinator-Subcommittee on Nutrition (ACC/SCN), 2010}.

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It is estimated that millions of people in the world are hungry, and that 848 million of the hungry people are in developing countries of Asia and Africa (WFP, 2009). In 2008 it was reported that most of the undernourished children were in developing countries, especially South Asia and sub- Saharan Africa, where prevalence of underweight children was 42 % and 28 %, respectively {United Nations Children’s Fund (UNICEF), 2008}. Therefore, ensuring unlimited access to adequate amounts of nutritious food is critical to health in sub-Saharan Africa.

1.6 Justification for the study

As indicated in section 1.3, inefficient storage technologies have been associated with major crop losses. However, in Tanzania, no practical verification that provides evidence to efforts being made to improve storage technologies especially at household level was found. Also, the quality of maize and its dietary importance in Katumba ward, and the capacity of storage methods that farm households in this ward use to protect stored maize against pests have also never been studied before.

Furthermore, as with other parts of Rungwe district Katumba ward is characterized by heavy rainfall (Mckone, 2002), and like the rest of the high zone of Rungwe district, it receives up to 2,700 mm of rainfall per annum (Administrator, 2010). Temperatures range between 10 - 25 ⁰C (Annon, 2008) almost throughout the year. The climatic conditions in Rungwe district encourage dampness and ultimately growth of moulds, which can lead to contamination of stored maize by mycotoxins and exposure of maize consumers to the mycotoxins. No study has been conducted before in Katumba ward to investigate the capacity of farmers to protect stored maize from moulds and mycotoxin contaminations. Furthermore, studies conducted on home - stored maize obtained from 120 households from Ruvuma, Iringa and Kilimanjaro regions of Tanzania in 2005 revealed the presence of unacceptable levels of aflatoxins (Kimanya et al., 2008). However, the mycotoxins were not associated with any storage method. Thus, this study attempted to fill the gaps indicated in this section.

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1.7 Research design

A case study of Katumba ward, Rungwe district, Tanzania was conducted in order to investigate the storage methods that subsistence farmersuse and the impact that these storage methods have on the quality of maize and food security of the farm households. The reason for the choice of a case study approach was because of its feasibility and the possibility of an indepth analysis of the research questions through group interaction (Bryman, 2004). Katumba ward was chosen because of the researcher’s long term involvement in agricultural activities in the ward. The question of the effectiveness of the storage methods used in the area and their impact on the quality of stored grains and food security in the area has always bothered the researcher. In order to enrich the research findings, both qualitative and quantitative methods were used. The application of both qualitative and quantitative methods for a study have been found to be effective in deepening understanding of research findings (Moore, 2006). While quantitative research focuses on numeric figures, qualitative reseach, on the other hand, focuses on studying perceptions and views of the population being studied (Galvan, 2006; Mouton, 1990). It also helps to explain the quantitative results such as providing answers to why and how things happen in specific contexts.

A combination of the qualitative and quantitative methods was expected to be more helpful in understanding how storage methods affect maize quality in Katumba ward than using the methods independently from one another.

1.8 Theoretical framework

In this study the ecohealth approach to human health was used. The ecohealth approach seeks to better understand how different components of the ecosystem namely: biophysical, socio- economic, and cultural systems relate, and how these interactions influence health and well being in specific contexts (Lebel, 2003). There are three pillars that the ecohealth approach focuses on, aimed at helping in understanding interactions between society and science in general and ultimately contributing to the improvement of health. These include interdisciplinarity, gender sensitivity and stakeholder participation for understanding ways in which socio-economic systems link with other ecological systems to influence health (De Plaen and Kilelu, 2004; Lebel, 2003).

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While interdisciplinarity is concerned with linking social and ecological systems, gender sensitivity has to deal with understanding roles that men and women play in specific contexts, and how these roles affect health. Stakeholder participation is concerned with involving stakeholders from the initial stage of the research for future action (De Plaen and Kilelu, 2004;

Bopp and Bopp, 2004). In general the ecohealth approach involves identifying key persons in specific contexts and studying the roles that they play in order to involve them in taking action for change. Due to the fact that this study is concerned with maize storage at household level, farm households were considered as the most important components of the stakeholders, thus, roles that individuals in the farm households play with respect to maize storage were of interest for this study. The ecohealth approach was considered appropriate for the purpose for this study, which ultimately aimed at improving maize storage methods and health of the community that was studied. Furthermore, the ecohealth approach was used because it is applicable and it has been applied before in other places in Africa such as Malawi and Egypt with good results (Kerr and Chirwa, 2004; Kishk et al., 2004).

1.9 Main Objective

The major objective of the study was to investigate the effects of storage methods on the quality of maize and the implications on household food security in Katumba ward, Rungwe district Tanzania. This study provides insights into storage mechanisms among poor communities and helps to understand how climatic conditions interact with storage mechanisms to influence household food insecurity in such communities.

1.10. Specific objectives

The specific objectives were as follows:

(i) To identify maize storage methods and investigate the associated storage problems focusing on pest infestation of stored maize and subsequent losses and their implications on the farm households’ food security.

(ii)To investigate farm households’ understanding of maize storage problems and the implications on the quality of stored maize and household food security.

(iii) To establish the dietary importance of maize and its contribution to household food security in Katumba ward, Rungwe district, Tanzania.

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(iv) To examine the quality of stored maize in terms of the presence of pathogenic species of fungi and levels of associated mycotoxins in maize and determine the implications on household food security from an ecohealth perspective.

(v) To evaluate the food security status of farm households and assess the farm households’

understanding of food security from an ecohealth perspective.

The following hypotheses were tested in this study:

(i) Due to the climatic conditions in Rungwe district, maize storage methods may be inadequate for keeping stored maize safe from pests and subsequent contaminations, thus, the quality of stored maize may be poor, and the farm households may be at risk of ill health, thus vulnerable and food insecure.

(ii) Traditionally, green bananas/plantains are the preferred food crop in Rungwe district.

However, maize production is gaining significance in this district, thus, maize consumption may also be rising, whereas farm households may not be well equipped in achieving and maintaining high quality of stored maize.

1.11 Research questions

The following research questions were addressed in this study:

 What are the maize storage methods that farm households in Katumba ward use for long term storage of maize and how much maize do the farm households harvest, store and or lose to pests during storage per annum?

 What are the main maize storage pests in Katumba ward and how do the farm households control them?

 What are the characteristics of the maize storage technologies that farm households use and how do the farm households perceive the storage technologies?

 What impact do the storage methods, the farm households’ perceptions of the maize storage methods and maize storage pests have on the quality of maize and household food security?

 Do farm households in Katumba ward have access to information concerning maize storage?

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 Are farm households in Katumba ward aware of diseases that are associated with consumption of foods that are contaminated with mycotoxins?

 How does the farm households’ awareness or lack of awareness concerning diseases that are associated with consumption of foods that are contaminated with mycotoxins influence their food security?

 What is the food security status of the farm households in Katumba ward and how do farm households understand food security and perceive their food security status?

 What are the reasons for the farm households’ perceptions concerning their food security status and how do the farm household’s perceptions and understanding of food security impact on their food security status?

 What importance does maize have in the diets of the farm households and how does this influence the farm households’ food security?

 What are the heads of farm households’ levels of formal education and what implications does the level of formal education have on maize storage and consumption?

 What is an average size of a farm household in Katumba ward and who are the key persons in the farm households as far as maize storage is concerned?

1.12 Organization of the thesis

The ‘papers’ format was utilized for writing up this thesis, thus, while the general introduction and the literature review apply to all of the chapters of the thesis, the chapters that deal with finding answers to the specific objectives of the study are further introduced at the beginning of each chapter. Furthermore, sections for the materials and methods, the presentation and discussion of findings, the conclusions and recommendations, the reference and appendices for the parts of the study that have been dealt with in each chapter have been provided for each chapter independently. However, in some cases the same materials and methods were used for finding answers to more than one of the specific objectives indicated above, thus, overlapping of the materials, methods and findings occurred in some chapters. In general, the Food Policy Journal (Elsevier), 2010 format was used, and the chapters are arranged as follows:

(i) Chapter One: Introduction (ii) Chapter Two: Literature review

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12

(iii) Chapter Three: The dietary importance of maize in Katumba ward, Rungwe district, Tanzania and its contribution to household food security¹.

(iv) Chapter Four: Maize storage problems and the quality of maize in Katumba ward, Rungwe district, Tanzania: implications on household food security

(v) Chapter Five: The importance and characteristics of roof and sack storage methods and their implications on household food security in Katumba ward, Rungwe district, Tanzania

(vi) Chapter Six: The effects of fungal infection and mycotoxin contaminations on the quality of maize stored using roof and sack storage methods in Katumba ward, Rungwe district, Tanzania².

(vii) Chapter Seven: Farm households’ food security status and the farm households’

understanding of food security in Katumba ward, Rungwe district, Tanzania.

(viii) Chapter Eight: Overview of the research findings

References

Adda, C., Borgemeister, C, Biliwa, A., Meikle, W.G., Markham, R.H., Poehling, H.M., 2002.

Integrated Pest Management in Post-harvest maize: a case study from the Republic of Togo (West Africa). Agriculture, Ecosystems and Environment. 93. 1 - 3, 305 - 321.

Administrator, 2010. Overview of the Council- Rungwe.

<http://www.mbeya.go.tz/index.php?option=com_content&view=article&id=173&Itemid

=190> (Accessed 2010 October, 10).

ACC/SCN, 2010. Sixth Report on the World Nutrition Situation. UN Standing Committee on Nutrition, Geneva.

Akande, K.E., Abubakar, M.M., Adegbola, T.A., Bogoro, S.E., 2006. Nutritional and Health Implications of mycotoxins in Animal Feeds: A Review. Pakistan Journal of Nutrition. 5, 398-403.

Amani, H.K.R., 2004. Agricultural Development and Food Security in Sub-Saharan Africa:

Tanzania Country Report. Economic and Research Foundation (ESRF), Dar-es-Salaam.

1Chapter Three (The dietary importance of maize in Katumba ward, Rungwe district, Tanzania and its contribtion to household food security) was published in the African Journal of Agricultural research. 6. 11, 2617-2626.

2 Findings from this chapter were published as follows: Rose Mboya, R., Tongoona, P., Yobo, K.S., Derera, J., Mudhara, M., Langyintuo, A., The quality of maize stored using roof and sack storage methods in Katumba Ward, Rungwe District, Tanzania:Implications on household food

A study of the effects of storage methods on the quality of maize and household food security in Rungwe District, Tanzania.